If I have a resting HR of 55 and another person has a resting HR of say 70, shouldn't our numbers and zone percentages be different?
Probably yes, but remember, that would be true even if you were actually talking about people of different age or gender as well.
But zones are zones and their purpose is to
broadly define exertion levels where differing balances of metabolic processes contribute to resulting heart rates. Other factors like rest, drugs and diet as well as the "training status" affect heart rate as well.
Resting heart rate, like maximum heart rate neither proves nor disproves the validity of anyone "zone selections." For most athletes its a trial and error learning process.